This routine is used find the next bit in a bitmap that is on. It is used
during the atomic restore of highmem pages.
Signed-off-by: Nigel Cunningham <[email protected]>
kernel/power/atomic_copy.c | 60 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 60 insertions(+), 0 deletions(-)
diff --git a/kernel/power/atomic_copy.c b/kernel/power/atomic_copy.c
index 07b418c..6d1bc68 100644
--- a/kernel/power/atomic_copy.c
+++ b/kernel/power/atomic_copy.c
@@ -75,3 +75,63 @@ static void suspend_init_nosave_zone_tab
}
}
+/**
+ * __suspend_get_next_bit_on: Atomic-copy safe location of next bit on in a bitmap.
+ *
+ * @bitmap: The bitmap we are traversing.
+ * @zone_num: Which zone we are in.
+ * @counter: The current pfn.
+ *
+ * A version of __get_next_bit_on that can be used when doing the atomic
+ * copy. While doing it, we can't rely on the zone information being in
+ * a constant location.
+ **/
+static unsigned long __suspend_get_next_bit_on(dyn_pageflags_t bitmap,
+ int *zone_num, long counter)
+{
+ unsigned long *ul_ptr = NULL;
+ int reset_ul_ptr = 1;
+ BUG_ON(*zone_num == num_zones);
+
+ if (counter == -1) {
+ *zone_num = 0;
+
+ /*
+ * Test the end because the start can validly
+ * be zero.
+ */
+ while (!zone_nosave[*zone_num].end_pfn)
+ (*zone_num)++;
+ counter = zone_nosave[*zone_num].start_pfn - 1;
+ }
+
+ do {
+ counter++;
+ if (counter > zone_nosave[*zone_num].end_pfn) {
+ (*zone_num)++;
+ while (!zone_nosave[*zone_num].end_pfn &&
+ *zone_num < num_zones)
+ (*zone_num)++;
+
+ if (*zone_num == num_zones)
+ return -1;
+ counter = zone_nosave[*zone_num].start_pfn;
+ reset_ul_ptr = 1;
+ } else
+ if (!(counter & BIT_NUM_MASK))
+ reset_ul_ptr = 1;
+
+ if (reset_ul_ptr) {
+ reset_ul_ptr = 0;
+ ul_ptr = PAGE_UL_PTR(bitmap, *zone_num,
+ (counter - zone_nosave[*zone_num].start_pfn));
+ if (!*ul_ptr) {
+ counter += BIT_NUM_MASK - 1;
+ continue;
+ }
+ }
+ } while(!test_bit(PAGEBIT(counter), ul_ptr));
+
+ return counter;
+}
+
--
Nigel Cunningham nigel at suspend2 dot net
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
